TY - JOUR
T1 - Antifouling diketopiperazines produced by a deep-sea bacterium, Streptomyces fungicidicus
AU - Li, Xiancui
AU - Dobretsov, Sergey
AU - Xu, Ying
AU - Xiao, Xiang
AU - Hung, Oi
AU - Qian, Pei Yuan
N1 - Funding Information:
This work was supported by grants (CAG04/ 05.SC01) from the Research Grants Council of the Hong Kong government and a Croucher Foundation Fund grant (CAS-CF03/04.SC01) and grant (COMRRDA 03/04 SC01) from the China Ocean Mineral Resources Research and Development Association to Pei-Yuan Qian.
PY - 2006/1/1
Y1 - 2006/1/1
N2 - Modern antifouling coatings use heavy metals and toxic organic molecules to prevent biofouling, the undesirable growth of marine organisms on man-made substrata. In an ongoing survey of deep-sea microorganisms aimed at finding low toxic antifouling metabolites, an actinomycete bacterium was isolated from the Pacific sediment at the depth of about 5000 m. The bacterium was closely related to Streptomyces fungicidicus (99% similarity) according to 16S ribosomal RNA sequence information. The spent culture medium of this bacterium inhibited barnacle larval attachment. Bioassay-guided fractionation was employed to isolate antifouling compounds. The ethyl acetate extract was fractionated by using an open silica gel column. Active fractions were further purified on a HPLC C 18 column. Five diketopiperazines, cyclo-(L-Leu-L-Pro), cyclo-(L-Phe-L-Pro), cyclo-(L-Val-L-Pro), cyclo-(L-Trp-L-Pro), and cyclo-(L-Leu-L-Val) were isolated for the first time from a deep sea bacterium, and the structures of the compounds were elucidated by nuclear magnetic resonance spectroscopy and mass spectrometry. The pure diketopiperazines were tested for antilarval activity using the barnacle Balanus amphitrite . Effective concentrations that inhibited 50% larval attachment (EC 50 ) after 24 h ranged from 0.10 - 0.27 mM. The data suggest that diketopiperazines and other compounds from deep-sea bacteria may be used as novel antifoulants.
AB - Modern antifouling coatings use heavy metals and toxic organic molecules to prevent biofouling, the undesirable growth of marine organisms on man-made substrata. In an ongoing survey of deep-sea microorganisms aimed at finding low toxic antifouling metabolites, an actinomycete bacterium was isolated from the Pacific sediment at the depth of about 5000 m. The bacterium was closely related to Streptomyces fungicidicus (99% similarity) according to 16S ribosomal RNA sequence information. The spent culture medium of this bacterium inhibited barnacle larval attachment. Bioassay-guided fractionation was employed to isolate antifouling compounds. The ethyl acetate extract was fractionated by using an open silica gel column. Active fractions were further purified on a HPLC C 18 column. Five diketopiperazines, cyclo-(L-Leu-L-Pro), cyclo-(L-Phe-L-Pro), cyclo-(L-Val-L-Pro), cyclo-(L-Trp-L-Pro), and cyclo-(L-Leu-L-Val) were isolated for the first time from a deep sea bacterium, and the structures of the compounds were elucidated by nuclear magnetic resonance spectroscopy and mass spectrometry. The pure diketopiperazines were tested for antilarval activity using the barnacle Balanus amphitrite . Effective concentrations that inhibited 50% larval attachment (EC 50 ) after 24 h ranged from 0.10 - 0.27 mM. The data suggest that diketopiperazines and other compounds from deep-sea bacteria may be used as novel antifoulants.
KW - Antifouling products
KW - Deep-sea bacteria
KW - Diketopiperazines
KW - Streptomyces fungicidicus
UR - http://www.scopus.com/inward/record.url?scp=33746795061&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33746795061&partnerID=8YFLogxK
U2 - 10.1080/08927010600780771
DO - 10.1080/08927010600780771
M3 - Article
C2 - 17290864
AN - SCOPUS:33746795061
SN - 0892-7014
VL - 22
SP - 187
EP - 194
JO - Biofouling
JF - Biofouling
IS - 3
ER -